A Chinese woman wearing a mask walks in a shopping street during a hazy day in Beijing city, China, on Tuesday. Beijing issued a red alert for smog, urging schools to close and residents to stay indoors for the second time in 10 days

An elevation in the city of Sarajevo, Bosnia and Herzegovina, covered in a thick layer of fog, on Monday. Due to high levels of NO2 (nitrogen dioxide) in the air over the city and a certain meteorological condition, residents of Sarajevo were recommended to reduce their movement in the streets and to reduce car traffic

A woman wears a mask as she visits the Forbidden City during a sunny day in Beijing Friday. Residents in the Chinese capital are preparing for its second smog red alert as a wave of smog is forecasted to settle over the city

A paramilitary policeman wearing a mask stands guard in front of the giant portrait of Chinese late chairman Mao Zedong, amid heavy smog after the city issued its first ever “red alert” for air pollution in Beijing, China

Chinese man wears a protective face mask as he passes by the CCTV building on a day of heavy pollution on Monday in Beijing, China. China’s capital and many cities in the northern part of the country recorded the worst smog of the year with air quality devices in some areas unable to read such high levels of pollutants

A crane can be seen over the VW logo on the administrative building of the Volkswagen factory in Wolfsburg. Thousands of VW diesel cars and gas engines might have used more gas and emitted more CO2 than stated by the manufacturer

Motorists ride on a road as thick haze from forest fires shroud the city in Palangkaraya, Central Borneo, Indonesia, Tuesday. The haze has blanketed parts of western Indonesia for about two months and affected neighboring countries like Singapore, Malaysia and Thailand

An Indian boy throws domestic garbage into the already polluted Yamuna river in New Delhi on Friday. Considered one of the holiest rivers in India, the Yamuna River has been dying a slow death from pollution for decades despite the investment of millions of dollars to preserve its ecosystem

A mother adjusts her daughter’s mask as they head home from school in Kertapati district in Palembang, on the Indonesian island of Sumatra. The worsening haze across northern Indonesia, neighbouring Singapore and parts of Malaysia forced some schools to close and airlines to delay flights this week, while Indonesia ordered a crackdown on lighting fires to clear forested land.

Dead fresh water fish, known as “popocha”, float in the Cajititlan lagoon in Jalisco State, Mexico. At least 25 tons of fish have turned up dead in the lagoon in western Mexico and authorities are investigating whether a wastewater treatment plant is to blame.

Vinicius, who is homeless, poses with his cat Nega on his bed where he sleeps on an abandoned ship floating on the polluted Guanabara Bay, the Rio 2016 Olympic Games sailing venue in Niteroi, Brazil. Following sicknesses to U.S. athletes during a recent rowing event and a study showing dangerous amounts of viral levels in all Rio Olympic water venues, the IOC has controversially ruled out the possibility of viral testing of the sewage-laden waters ahead of the Olympics. Abandoned vessels have been linked to various environmental hazards.